1. Technical Field
The present invention relates to a method for manufacturing a semiconductor device or a semiconductor wafer.
2. Related Art
Conventionally, in manufacturing process of semiconductor device or semiconductor wafer, surface or edge portion of the wafer is polished to improve the shape, cleanliness and so on. One surface of a semiconductor wafer is chucked to a chucking unit while a polishing process is carried out. The chucked surface is expressed as “back surface” hereafter. Here, slurry employed for the polishing process penetrates into the back surface of the semiconductor wafer. When a back surface is dechucked from a first chucking unit, the wafer is transferred to a second chucking unit, and then is chucked to a second chucking unit for subsequent polishing processing without cleaning process, the slurry adherently remained on the back surface of the semiconductor wafer is firmly stuck on the back surface of the semiconductor wafer. To solve the problem, for example, the semiconductor wafer just after a bevel-polishing of the edge is immersed into a water bath in keeping the wafer chucking to the chucking unit, and the chucking unit is rotated. A method for removing slurry adherently remained on a semiconductor wafer or a chucking unit is proposed by such procedure (see, for example, Japanese Patent No. 3649531). Besides, for example, another method is also proposed, which includes dechucking a polished semiconductor wafer from a chucking unit, immersing the wafer into a water bath, and shower cleaning and scrub cleaning the back surface of the semiconductor wafer (see, for example, Japanese Patent Laid-Open No. 2005-74574).